Telephone-transmitter-arm joint.



No. 680,077. Patented Aug. 6, I90I.

H. B. SABIN.

TELEPHUNE'TRANSMITTER ARM JOINT.

(Application 'flled Jan. 28,' 1901.)

(No Modal.)

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- WITNESSES.-

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srncrrrcarron formingpart of Letters Patent No. 680,077, dated August 6,1 901.

- Application fine January 28,1901. Serrano. teens. .(Nomodehl To (all whom it may concern.-

Be it known that I, HERBERT B. SABIN, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Telephone-Transmitter- Arm Joints; and Ido hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

' being shown.

My invention relates to improvements in telephone-transmitter-arm j oint-s, by which term is meant the joint by which the movable arm carrying the transmitting-mouthpiece is secured to. the base by being pivoted between the two logs with which the base is ordinarily provided.- 7

The object of the invention is to improve the construction, to avoid the defects found in previous constructions, and to secure a simpler, cheaper, and more efficient joint than heretofore employed; and the invention consists in the construction and combination of parts, ashereinafter fully described; and specifically pointed out in the claims.

In the drawings, Figure 1 represents in end elevation the lugs and upper part of a transmitter-arm base and the lower part of the arm pivoted between thelugs thereof, the remaining portions of the arm and base not Fig. 2 represents in central vertical section the construction of the joint shown in Fig. 1, and Figs. 3 and 4 represent in side view the structure. shown -vin Figs. 1 and 2. o

A represents the base, 66 a, the lugs thereon, between which the arm B is pivoted. In order that thearm B should be readily capable of movement on its pivot and at the same time be so firmly held as to remain in the position in which it is placed Without being displaced by accidental causes, it is essential that the joint should be one which shall have sufficient friction to maintain the arm 'in'position and yet not bind the arm so tightly as to prevent its easy movement, When the arm is pivoted between the lugs simply by means of a screw passed through the lugs and entering the arm or by means of a pivot passed thrbugh the arm and lugs and havinga nut on each end outside of the lugs, it

' has been found practicallyimpossible to keep the nut from working loose unless provided with a check-nut, which of course takes up additional room and is besides objectionably clumsy in appearance. In or der to dispense with the check-nut, a spring interposed between the arm and lugs, so as to give the necessary friction and yet permit of easily moving the arm, has been employed; but it has been found that such construction is unsatisfactory in use, for the reason that the spring is liable to break or lose its tension and its use adds materially to the labor and expense involved in joining the arm to the base; also, the tension of the spring aids in working loose the screw,which secures the base to the lug, owing to the absence of a check-nut. Inasmuch as compact construction having as few parts as possible and no projecting parts that can be avoided is especially desirable in telephone-arm construction, it is one object of my invention to dispense with the unsatisfactory and objectionable spring and to obtain the advantages of using a checkmut without increasing the space occupied therefor and without the ap pearance of the use of a check-nut. To accomplis'h the foregoing objects, I provide the base of the arm B on each side with a conical depression, and I thread through the lugs a a conical-pointed screw 0, which may be headed, but is preferably straight and slotted,

as shown in Fig, 2, and which in any case is.

, bled, and I thread upon the projecting part of the screw 0 a nut (Z, which occupies substantially no greater space than would be occupied by the head of an ordinary pivotscrew, but which forms an eifective lock-nut to prevent the loosening of the screw 0 by movement of the arm B. The nut- (I may be solid, but preferably is capped by an ornamental covering-cap e, forced upon the nut d, and which cap, being imperforate, gives an exceedingly neat and pleasing finish and may, if desired, be ornamented in any suitable way-for instance,-the cap may be circular and provided with a milled edge or rim f.

By the foregoing construction I accomplish the following desired results: First, the conany other construction, and especiallyfwhere ical point of the screw c, fitting in the conical depression I) in the arm B, affords a smooth easy-acting joint, having much less friction than where a spring is employed. In the second place, the movement of the arm B upon the conical point has practically no-tendency to loosen the'screw 0, whereas any screw threaded into the arm orinto thelugs alone, it the spring is used, is certain to work loose if unprovided with a check-nut. In the third place, the employment of the check-nut d practically prevents theworkin g loose of the screw 0; but if it should occurby removing the check-nut d and turning up the screw 0 to the proper hearing and replacing the check-nut cl the readjustmentis effected more readily than with springs aroused, since the complete rernjoval of oneof the screwsc will not permit the arm B to become displaced, as the opposite screw will hold it. Finally, in addition'tothesavmg in nuniber of parts and in labor andeX- pense of making the same there is a saving in amount of machine-work requiredjtofit the base B to the lugs a, as no recesses for; the

, springs or other work has to bennade. .By

"and. obtain all the advantages thereof with out the structure having the appearance of a 7 3o check-nut nor occupying the room'ordinarily this means I am enabled to use a" check-nut needed therefor. .i

What I claim asiny invention, and desire to-secure by Letters Patent, is

1-. In a, pivoted transmitter-arm joint, the combination of the arm seating between the lugs of the base and having 'oneach side a conical depression, screws threaded through the lugs and projecting outside the sa ine, said I screws having conical points entering and fitting the conical depressions in the arm, and nuts threaded on said screws outside the lugs and serving as lock-nuts without occupying more space than a single nut, substantially as described.

2. In a pivoted transmitter-arm joint the combination of the arm'se'ating between the lugs of the base and having on each side a conical depression, screws threaded through the lugs and projecting outside the same, said screws having conical points entering and conical depression, headlessscrews threaded through the lugs and projecting outside-the same, said "screws having. conical points Yen- .tering and fitting the conical defn'essions in 'the'arm, and nuts threaded on said screws outside the lugs and; serving as lock -nuts without occupying more space than a single nut nor extending beyond the shoulder of the; base, substantially. as described.

combinationof the arm seating between the} lugs of the lo'a's'eand havingon each side a;' .tOOlllGitl depression, headless screw-s threaded; 'throu gh the-,l ugs 'and fprojecting outside the: 'saui'e,- said screws having conical points em teringand fitting the conical depressionsinthe arm, and 'capped nuts-threaded on said screws voutside thelngsiand having no exterior opening,;whereby the nutsserve as lo'ckf nuts without the appearance thereof and with= out occupying more spa-ce'than a singlenut nor extending beyond the shoulde'rof the base, substantially as described.

' to affig my sig- In testimony whereof I- here nature in presence oi two'witnesses.

I "HERBERT B. sABiN.

\Vitnessesr Y I R. O. HARTSHORNE,

IIAT IE A. STEVENSON.

. 7 fitting the conical depressions in the arm, and 

